The present invention relates in general to calibration techniques, and in particular to a new and useful device and method for automatically calibrating an orifice or flow meter.
Glass orifices are known which are used in various fields of technology. Some small orifices are burned with a laser through a small stainless steel disc. The disc can conveniently function with an orifice holder for attaching the orifice to calibration equipment or alternately to the equipment in which the orifice is to be used.
Up to the present time, such orifices have been calibrated using a tedious manual method. Such a method requires an inordinate amount of time to accomplish and is vulnerable to operator error.
In the manual flow method, a soap bubble membrane is created in a tube and the membrane is observed as it passes two points of the tube. The volume between these two points is known. The elapsed time is recorded with a stopwatch. This yields the volume per unit time or flow rate. Flow is established by drawing fluid from the tube and through the orifice.
A technician who practices the soap bubble method must be present to visually note and record elapsed time and volume. Observations are subject to human error. Frequently the bubble membrane will burst. This requires the formation of a new bubble membrane and restarting of the method.
Atmospheric conditions also affect the sucessfully developed bubble membrane. The procedure is also time consuming since the technician must personally attend to the apparatus continuously.